A study on the gelation behavior of solutions of native gellan, deacylated gellan, and their mixture by water 1H T2 measurements

A study on the gelation behavior of solutions of native gellan, deacylated gellan, and their...
Hu, Bingjie; Lu, Yang; Zhao, Qiuhua; Matsukawa, Shingo
2017-11-01 00:00:00
The temperature dependence of water 1H T2 for native gellan (NG), deacylated gellan (DG), and a mixed solution of NG and DG in the presence of various concentration of Ca2+ were measured by NMR. The results showed that DG formed a network of aggregates more drastically and at lower temperature than NG. The water 1H T2 of the mixture showed a two-step decrease during cooling but not during reheating, indicating that DG and NG separately formed aggregates during cooling and that both DG and NG disaggregated at similar temperatures during reheating. In spite of the two-step gelation process in the mixed solutions, the water signals decayed mono-exponentially at each temperature during cooling. This suggests that the network structure formed either an interpenetrating structure or a phase separated structure with the scale less than the diffusion distance of water within the 1H T2 relaxation time where the water relaxation behaviors affected by DG and NG chains were averaged to show the mono-exponential decay.
http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.pngFood HydrocolloidsElsevierhttp://www.deepdyve.com/lp/elsevier/a-study-on-the-gelation-behavior-of-solutions-of-native-gellan-xWuidjPyDa

A study on the gelation behavior of solutions of native gellan, deacylated gellan, and their mixture by water 1H T2 measurements

Abstract

The temperature dependence of water 1H T2 for native gellan (NG), deacylated gellan (DG), and a mixed solution of NG and DG in the presence of various concentration of Ca2+ were measured by NMR. The results showed that DG formed a network of aggregates more drastically and at lower temperature than NG. The water 1H T2 of the mixture showed a two-step decrease during cooling but not during reheating, indicating that DG and NG separately formed aggregates during cooling and that both DG and NG disaggregated at similar temperatures during reheating. In spite of the two-step gelation process in the mixed solutions, the water signals decayed mono-exponentially at each temperature during cooling. This suggests that the network structure formed either an interpenetrating structure or a phase separated structure with the scale less than the diffusion distance of water within the 1H T2 relaxation time where the water relaxation behaviors affected by DG and NG chains were averaged to show the mono-exponential decay.

Journal

Food Hydrocolloids
– Elsevier

Published: Nov 1, 2017

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References

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